Chlorination of ethylene chloride



Patented Dec. 20, 1938.

- UNITED STATES PATENT OFFICE CHLORINATION 0F ETHYLENE CHLORIDE John H. Reilly, Midland, Mich., assignor to The Dow Chemical Company, Midland, Mich., a corporation of Michigan 1 No Drawing.

Application March 19, 1937,

Serial No. 131,823 3 Claims. (01. 260-658) This invention relates to processes for the chlorination of ethylene chloride; and, more particularly to a process .for the conjoint preparation of 'diand tr-i-chloroethylene from ethylene chloride.

My improved process for the chlorination of ethylene chloride comprises the steps of passing ethylenechloride and chlorine in certain ratios, preferably in the vapor phase; into contact with molten metal chlorides which are at a tempera ture in the range between about 400 and about 480 C. The ratio of chlorine to ethylene chloride is preferably in-the range between about 0.7 and 1.0 pfiirby weight of chlorine per part of ethylene chloride. The ethylene chloride and chlorine may be preheated separately, or in admixture, toany desired temperature up to reaction temperature before they are passed into the molten salt bath.

The bath in which the reaction is carried out comprises one'or more of the chloridesof aluminum, potassium, iron,'sodium, bismuth, zinc, and other metals, such chloride or mixture of chlo rides being freely fluid at the reaction temperature. The eutectic produced by mixing 60 parts by weight of aluminum chloride, parts by weight of sodium chloride, and 10 parts by weight v ,of ferric chloride is suitable. This eutectic has a melting point of about C. and a boiling point above 1000 C. A mixture of 30 parts by weight of sodium chloride and '70 parts by weight of Zinc I chloride can be used alone as the bath. The re-' action here involved is exothermic in character aluminum chloride is .equally suitable.

andis capable of developing enough heat to maintain the-salt bath at temperatures in the, range above given uiider ordinary conditions. In fact.

- cooling maybe necessary when highrates of flow of'reactants are employed. .1

The following example illustrates of my invention: The bath employed was composed of 36 parts by weight of potassium chloride and 64 parts by weight of aluminum chloride. It-

was approximately inches in depth and weighed ten pounds. A mixture of ethylene chloride and chlorinein the ratio of about 0.93 part by weight of chlorine per part of ethylene chloridewas continuouslyled into the bottom of said bath at a substantially uniform rate of about 1470 grams per hour, the bath being maintained at a temperature of about 450 C.

The gaseous reaction product the Practice 400 and about 480 C.

was cooled to.

'of diand tri-chloroethylene.

By operating in a like bath at a temperature of approximately 450 C., with a chlorine to ethylene chloride ratio of 0.75 to 1.00, I have ob- Other modes of applying the principle of my invention may be employed instead of the one explained, change being made 'as regards the tained results similar to those shown in the above example.

method herein disclosed, provided the step or steps stated by any of the following claimsor the equivalent of such stated step orsteps be employed..

I therefore particularly point out and distinctly claim as my invention: 1

1. In a process for the conjoint preparation of diand trichloroethylene, the step which consists in passing chlorine and ethylene chloride, in the ratio of between about 0.7 and about 1.0 part by weight, of chlorine per part of ethylene chloride, into a molten metal chluide bath maintained at a temperature betweenabout 400 and about 480 C. q t

2. In a process for the conjoint preparation of diand trichl'oroethylene, the step which consists in passing a mixture of chlorine and ethylene chloride, in the ratio of between about 0.7 and about 1.0 partby weight of chlorine per'part of ethylene chloride, into a molten metal chloride bath maintainedat a temperature betweenabout 3 The process which .comprises preheating, ethylene'chl oride to a temperature notsubstantially above-400 C., admixing chlorine'tl'ierewith I in-the ratio between about 0.7 and about 1.0 part by weightof chlorine per part of ethylene chlor'ide,-and passing said mixture into a bath of molten metal chloride maintained at a temperature between about'400 and about 480 C.

- t JOHN H. REIILY. 

